Air conditioning apparatus



Sept. 3, 1940. H. 551D 2,213,350

` AIR CONDITIONING APPARATUS l Filed May 12,11958 BY 244mm@ ATTORNEY4 Patented Sept. 3,- 1940 UNITED STAT-Es PATENT OFFICE Herman Seid, New York, N. Y., assignor to Auditorium Conditioning Corporation, Jersey City, N. J., a corporation of New Jersey' Application May 12, 193s, semina. 207,516

' 1 claim. eicel- 2) This invention relates to air conditioning.

The general object of the invention is to provide an air conditioning apparatus for controlling the moisture content of air or other gas which is to be conditioned.

In the conditioning of enclosures occupied by persons whose comfort and health are primary considerations, it is necessary that a quantity of outdoor air be supplied to such enclosures at all times, in order to meet the ventilation requirements oi the occupants. Under summer operating conditions lin most localities the fresh air thus supplied is usually hot and humid and requires reduction of its moisture content in order that it may be used to create and maintain comfortable atmospheric conditions within the enclosures. Also, in cooling enclosures for comfort, it is common practice to recirculate a portion of the air Withdrawn from the enclosure. In conventional v installations the quantity of air thusre-circulated may be of the order of four or ve times the quantity of fresh air introduced into the enclosure. In its circulation through the occupied enclosure, the conditioned air is subject to a substantial increase in moisture content, due to the evaporation of water from the bodies of the occupants,

as is well understood. Thus, in order that it maybe suitably prepared for resupply to the enclosure, this air withdrawn from the enclosure for recirculation must also have its moisture content reduced in order that comfortable atmospheric conditions may be created and maintained in the enclosure.

Similarly,v in certain industrial applications of air conditioning it is necessary to remove moisture from the air in order to provide desired atmospheric conditions.

Reduction of the moisture content of the air may be accomplished broadly by either of-two 40 methods. namely, dehumidication and dehydration. When the air is dehumidiied, it is subjected to heat exchange with a cooling medium or refrigerant which reduces the dry bulb temperature of at least some of the air below the original dewpoint of the air, thus precipitating moisture from the air. 'Ihis method has they disadvantage that the cooling process and the process of moisture reduction are denitely and inseparably interrelated, thus creating control problems.

Further, the air which hasbeen dehumidied is necessarily at a relatively low dry bulb temperature and hence, in most applications, must be reheated before it may be introduced into the enclosure to be conditioned. I

An object of the present invention is to provide an apparatus for reducing the moisture content of air to be conditioned by dehydration, without cooling the air. Thus, the necessity for reheating is eliminated. Also, the process of moisture reduction is divorced from the process of con- 5 trolling the temperature, so that these may be controlled independently. Accordingly, control problems are simplified.

Another object of the present invention is to provide an improved apparatus for conditioning 10 air in which a liquid absorber is used. 'I'his process is based upon the fact that hygroscopic solutions as, for example, solutions of lithium chloride and calcium chloride, when they are brought in contact with air having a higher vapor pressure, l5

will absorb moisture from the air with which they contact. As such a solution absorbs moisture from the air, due to the diierence in the respec` tive vapor pressures of the solution and of the air, the solution is diluted so that its vapor pres- 20 sure is increased and its capacity for absorbing water from the air is decreased. In order that the solution may be kept at the proper strength, heat must be supplied to the solution in sufficient amount to evaporate excess moisture from the 25 solution.

Accordingly. a feature of the invention resides in the provision of means for evaporating moisture from an absorber solution, thus to increase the density a-nd vapor pressure of the solution, 3o whereby it may function effectively to absorb moisture from air with which it is contacted.

Another feature of the invention resides inthe provision of a pair of substantially identical units, each'of which is adapted to serve as an air con- 35 ditioning unit. 'Ihese are arranged to operate alternately, so that as absorber solution in one of the units is being regenerated, air to be conditioned may be circulated with desired eifect through the other unit. 40

Other objects and features of the invention will be more apparent from the following description to be read in connection with the accompanying drawing, in which Fig. 1 diagrammatically represents an eleva- 45 tional view partly in sectionoi' apparatus in accordance with the invention, and

Fig. 2 diagrammatically represents a plan view partly in section of the embodiment of the invention illustrated in Fig. 1. 5g

Referring to the drawing, the numerals i and 6 designate generally two substantially identical air conditioning umts arranged preferably in close proximity to or adjoining each other. Air to be conditioned is drawn through the units i and I 55 dividually controlling the under the iniiuence of fan 1 actuated by motor 9, and the conditioned air is then delivered to an enclosure to be conditioned (not shown) through duct 9. The opposite ends of unit 5 are provided respectively with an inlet opening I0 and an outlet opening Il for air circulating therethrough. Similarly, unit 5 is provided with an air inlet opening I2 and an air outlet opening I9.

The openings I0 and II are provided respectively with dampers Il and I5, adapted, when closed. to completely cut oil the circulation of air through unit 5. Similarly, openings I2 and I9 are provided with dampers I6 and I1, respectively. The dampers Il and I6 are differentially connected in any suitable manner, so that when dampers Il are closed, dampers I6 are opened, and vice-versa. Similarly, dampers I5 and I1 are differentially connected so that when dampers I5 are closed, dampers I1 are opened, and vice-versa. Dampers Il and I5 are connected in such manner that they are either opened or closed together. Thus, air may ow at any given time through either unit 5 or unit 6, but not through both of the units at the same time. a 1

Unit 5 is provided with a spray device i9 for ,spraying the air passingthrough unit 5 with a moisture-absorbing salt solution of such a substance as lithium chloride or calcium chloride. This sprayed solution falls into the bottom of unit 5 which constitutes a sump I9 from which the solution is withdrawn by pump 2li for resupply through pipe 2| to the spray device I9. Pump 20 is actuated by a -suitable electric motor or the 1ike,.22. Similarly, unit 6 is provided with a spray device I8a, a sump I9a, motor 20a, pipe 2Ia and motor 22a. Beneath unit 5 and tion in sump I9 thereof, is device such as gas burner tioned beneath the sump I9a of unit 6 is gas burner 23a. The burners 23 and 23a are supplied with fuel through feed line 24 in which there is interposed a valve 25. valve 25 is arranged to supply fuel to gas burner 23 or 29a, but to only one of these burners at any given time. As will be understood, a pair of valves insupply of fuel to the burners 23 and 23a could be provided without departing from the essence and spirit of the invention.

As is known; the absorption of moisture by a solution' such as lithium chloride changes the moisture in the air from vaporous form to liquid form, thus releasing the latent heat of vaporisation of such water vapor. 'I'he heat thus released tends to increase the temperature of the air being dehydrated. `'li'o offset this tendency of the air temperature to rise, due to the dehydration process, there'is provided a cooling element such as coil 26 in the unit 5. provided with a ing medium, such as cold water from a city main or the like, is adapted to be supplied to the coils 29 and 26athrough supply line 21. Supply line 21 is adaptedto supply cooling medium selectively either to coil 29 or to coil 26a, due to the provision of controlvalve 29. As will be understood and as explained in connection'with the supply of fuel to the gas burners, a pair of valves individually controlling the supply of fluid to the coils 29 and 26a might be substituted for the valve 28 without departing from the scope of the invention. Water which has circulated through the `coils 26 and 26a is discharged through a suitable drain pipe 29. The coils 2l and 29a adapted to heat the solupositioned a heating '23. Similarly posiaaisso of regeneration of cooling colina. Suitable coolregeneration 4connects to a are preferably provided with extended surface such as spiral or plate ilnning whereby to increase their heat transfer capacity. It, is preferred to place the spray devices Il and Ila at a higher level than the coils 25 and 25a in order 5 that the coils may cool not only the air circulating through the units 5 and 5 but also may cool the absorber solution delivered from the spray devices and falling in contact with the coils 25 and 29a. Further, such wetting vof the coils increases their'cooling capacity.

In the sump of each unit there is provided a suitable means for indicating the degree of dilution of the solution contained therein. Thus. the sump I9 is provided with a hydrometer Il and the sump I9a is provided with a hydrometer 99a. As above explained, one of the units will be operative for conditioning air while the other is inoperative for this purpose but isbeing prepared for such service. Therefore, at all times during operation of the apparatus, one of the hydrometers will indicate a relatively low density of absorber solution while the other will respond to a density sufficiently high to enable the absorber solution properly to effect its desired water absorbing operation. Since the condition of the absorber solution in the respective units 5 and 5 determines which unit is to be operative at any given time, the hydrometers 30 and 90a, which respond to solution densities, are utilized selectively to control the operation 'of the two units.

Thus, when the absorber solution in sump Ila.

has a sufciently high density to abstract mois ture from air passed through unit l6 in an efficient manner, the hydrometer 30a reectingthls $5 condition will, through suitable controls associated therewith, operate the dampers so that dampers I6 and I1 are in opened position, and dampers Il and I5 in closed position. Thus, air may circulate through the unit 5 and not through the unit 5. The dampers may be operated by any suitable damper control mechanism, indicated generally as 3|. Also. hydrometer 29a through electrical switch 92 will energize motor 22a, thus to operate the pump 20a which circulates absorber solution. from the sump I9a to the spray device I9a. Hydrometer 35a will also actuate valve 28 so that cooling medium from pipe 21 will be circulated through coil 25a. in unit i and not through coil 25 in unit 5.

During the period when unit l is operative for conditioning air passing therethrough, the absorber solution in unit 5 `is regenerated in preparation for resumption of its air conditioning function. Accordingly hydrometer 29a, during the period when unit l is operative for air conditioning purposes, adjusts valve 25 in the fuel supply line 24 so that fuel is supplied to the burner '23 serving the unit 5. During the period units I, the pump 2| is rendered inoperative.

There is provided an exhaust fan 29 actuated by. motor or the like, 3l. which serves to draw off and exhaust moisture evaporated during the process. Accordingly', the fan Il 0r,

duct 35 having a branch 3l connecting Vwith unit 5 and a branch a connecting with unit 9. A damper 91 is provided for selectively providing communication between the fan 33 and one or the other of the units. During the period whenlmit 5 is being regenerated, the damper 31 is in the positionshown to providecommunication between the fan I3 and the unit 5, so that moisture evaporated from solution in sump I9 may be readily'discharged to the out- 75 lao door atmosphere or,otherwise suitably disposed of. It may be noted that the pressure `reduction within the unit 5 due to the action of fan 33 serves to facilitatethe evaporationof moisture by lowering the boiling point of the water. If it is desired to circulate air through the unit 5 during regenerating periods aninwardly opening flap valve 38 may be provided in conjunction with a suitable opening 39 formed in the Wall of the casing of unit 5.

Since the control elements per se used to control the valves 28 and 25, damper actuating` device 3|, selective electrical switch 32 and damper 31 are well-known and understood, no further description of these elements is deemed necessary here.

vWhen the solution circulated through unit 6 has become so diluted by its contact, over a period of time, with air passing through the unit, the solution in unit 5 will be ready for active air conditioning service, due to its regeneration. Accordingly, hydrometer acting in response to the increased density of the solution in sump I9 will open dampers I4 and I5, thus to permit air ow through unit 5, and close dampers I6 and I1, thus to shut olf the flow of air through unit 6. Also, hydrometer 30 Will then operate switch mechanism 32 to cut motor 22a out of service and to render motor 22 operative, thus to cause pump 20 to circulate absorber solution through unit 5. Hydrometer 30 will also actuate directional valve 25 so that regenerating fuel Awill be supplied to the burner 23a serving unit-6. Damper 31 will be adjusted so as to prevent air ow through duct branch 36, thus placing the unit 6 in communication with exhaust fan 34. As in the case of I unit 5, an inwardly open flap valve 38a serving an opening 39a may be provided, if desired.

After the unit 5 has been in `operation for a predetermined period, the sequence of operations will again be reversed so that unit `6 becomes operative and unit 5 inoperative, and this alternate operation of the two units will continue throughout the time during which air conditioning is required.

As will be understood, suitablel pilot lights may be provided for the burners 23 and 23a. Also, it will be understood that instead of the hydrometers 30 and 30a, suitable float ,devices may be used to indicate the density of the solution. This follows from the fact thatgthe salt with which each unit is initially charged remains within the unit, andhence the liquid level in the unit gives a direct indication of the density of the solution.

IfY desired, a valve 40 in a cooling medium supply line 21 mayibeyprovidedto control quantitatively the supply of 'l cooling-'medium to the coils 26 and 26a. Preferably, valve 40 is controlled thermostatically, as, for example, by thermostat 4I placed in the air supply duct 9 or at any other desired point in the air conditioning system.

i The bottom portions of the units 5 and .6 are preferably formed of material having a relatively high heat conductivity, such as metal, in order that the units 5 and 6 may serve both as air conditioning chambers and as regenerating chambers to which heat is supplied from the burners 23 and 23a.

While as shown and described, the pumps 20 and 20a are operative at different times so that absorber solution is circulated through a passageway only when air to be conditioned is circulated I through such passageway, it may be ,desired to operate the pumps during the regenerating period of the operating cycle as Well as during the air conditioning period of the cycle. Circulation of heated absorber solution by the pumps to and through the spray devices assists in the liberation of Water vapor from the solution and hence tends to hasten the concentration of the solution.

Since many changes may be made in the invention without departing from its scope, it is intended that all matter contained in the above description or shown in the accompanying drawing shall be interpreted as illustrative only and .not in a limitingrsense, applicant limiting him-` self only as indicated in the appended claim.

I claim:

A continuous cycle air dehydration and cooling system comprising a conditioning chamber divided into two compartments by a partition wall, adsorber solution in a su'mp portion of each compartment, a pump connected with each compartment and spray producing means in the upper part of each compartment served by the respective pump servingthe compartment, a cooling coil in each compartment positioned above the sump area and beneath the spray producing means, a common exhaust passage having a pair of branch ducts, one branch duct connecting to the rst compartment, the other branch duct connecting `to the second compartment, a damper for consponsive to conditions within said compartments.

for causing the pump and spray producing means and cooling coil for one of said compartments to be active while the corresponding apparatus for the second compartment remains inactive and simultaneously for causing the fuel supply means to serve the second compartment and the branch duct from said second compartment to connect with the common exhaust passage while fuel is cut oil' to the rst compartment and the branch duct therefrom remains closed.-

HERMAN SEID. 

